Biomaterial Database

Population cytogenetics of folate-sensitive fragile sites. I. Common fragile sites. 1988

M Kähkönen

Department of Clinical Genetics, Oulu University Central Hospital, Finland.

The location and frequency of folate-sensitive common fragile sites (CFS) were studied in three populations: (1) 111 mentally retarded children of school age, (2) 240 mentally subnormal children attending special schools, and (3) 85 healthy children attending normal schools. Common fragile sites were found at 54 chromosomal bands including also the band Xq27, where gaps and breaks were detected in 4% of the children. The most frequent CFS were FRA3B (at 3p14.2), FRA6E (at 6q26), and FRA16D (at 16q23) seen in 73%, 65%, and 58% of the individuals totally studied. The frequencies of CFS-positive individuals did not differ among the populations. The variation found in the distribution of CFS among the populations was primarily assumed to be due to sampling differences and study method. The rate of expression of the most frequent CFS varied significantly among the individuals, seeming to suggest that polymorphism exists at those CFS.

UI	MeSH Term	Description	Entries
D011110	Polymorphism, Genetic	The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.	Gene Polymorphism,Genetic Polymorphism,Polymorphism (Genetics),Genetic Polymorphisms,Gene Polymorphisms,Polymorphism, Gene,Polymorphisms (Genetics),Polymorphisms, Gene,Polymorphisms, Genetic
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D002873	Chromosome Fragility	Susceptibility of chromosomes to breakage leading to translocation; CHROMOSOME INVERSION; SEQUENCE DELETION; or other CHROMOSOME BREAKAGE related aberrations.	Chromosomal Fragility,Fragility, Chromosomal,Fragility, Chromosome
D005492	Folic Acid	A member of the vitamin B family that stimulates the hematopoietic system. It is present in the liver and kidney and is found in mushrooms, spinach, yeast, green leaves, and grasses (POACEAE). Folic acid is used in the treatment and prevention of folate deficiencies and megaloblastic anemia.	Pteroylglutamic Acid,Vitamin M,Folacin,Folate,Folic Acid, (D)-Isomer,Folic Acid, (DL)-Isomer,Folic Acid, Calcium Salt (1:1),Folic Acid, Monopotassium Salt,Folic Acid, Monosodium Salt,Folic Acid, Potassium Salt,Folic Acid, Sodium Salt,Folvite,Vitamin B9,B9, Vitamin
D005787	Gene Frequency	The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.	Allele Frequency,Genetic Equilibrium,Equilibrium, Genetic,Allele Frequencies,Frequencies, Allele,Frequencies, Gene,Frequency, Allele,Frequency, Gene,Gene Frequencies
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D043283	Chromosome Fragile Sites	Specific loci that show up during KARYOTYPING as a gap (an uncondensed stretch in closer views) on a CHROMATID arm after culturing cells under specific conditions. These sites are associated with an increase in CHROMOSOME FRAGILITY. They are classified as common or rare, and by the specific culture conditions under which they develop. Fragile site loci are named by the letters "FRA" followed by a designation for the specific chromosome, and a letter which refers to which fragile site of that chromosome (e.g. FRAXA refers to fragile site A on the X chromosome. It is a rare, folic acid-sensitive fragile site associated with FRAGILE X SYNDROME.)	Fragile Sites, Chromosome,Chromosome Fragile Site,Fragile Site, Chromosome,Site, Chromosome Fragile,Sites, Chromosome Fragile